RE: I don't like Primanti Bros. in Pittsburgh
Err, actually, this is a fairly poorly reasoned post
Primanti's, whether you like it or not, is a local institution revered for it's food. They do indeed have a large dedicated following. If another sandwich shop opens up down the street ALSO servng overstuffed sandwiches, few if any of these dedicated customers will make the switch.
McDonald's is neither local nor revered (by stockholders? maybe. foodies? not so much). The horde of people who go there go because the prices are cheap and the locations are all over, not because the food is great. They are not a "dedicated following" - if something just as good and as cheap and as easily accessible came along, they'd go there instead.
The two are not comparable. Sorry.